JP2767511B2 - Background removal method for inductively coupled plasma mass spectrometer using heated vaporizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for removing the background of an inductively coupled plasma mass spectrometer using a heated vaporization introducing device.

[0002]

BACKGROUND ART heated and vaporized introduction device for introducing an analyte to an inductively coupled plasma mass spectrometer, heating an analyte in accordance with a predetermined heating profile PR ₃ as shown in FIG. 4,
Vaporize. The heating profile PR ₃ is dry stage S.alpha, the solvent was removed in an ashing stage S [beta, vaporizing the analyte at higher temperatures of vaporization stage S [gamma]. The vaporized analysis target is introduced into an inductively coupled plasma mass spectrometer together with a carrier gas of argon (Ar).

The problem here is that, for example, if the object of analysis is iron (Fe), the carrier gas Ar and O of H ₂ O, which is the solvent of the analysis sample, combine to form a bond ion ArO. Since the mass number becomes substantially equal to ArO,
O is detected as a background of Fe.
Detection sensitivity decreases. To solve this problem,
Preparing a plurality of types of heating profiles in which the conditions of the drying stage Sα, the incineration stage Sβ, and the vaporization stage Sγ are changed, and heating the analysis target a plurality of times to remove ArO as a background. I have.

[0004]

However, the above-described conventional background removing method has the following problems. That is, in the conventional method of removing the background, it is necessary to perform heating using a plurality of types of temperature rising profiles, and it takes time and effort. In addition, the bonded ions serving as the background (A in the above case)
Since the temperature at which rO) is detected is not known, when a plurality of types of elements are analyzed at the same time, changing the temperature rise profile becomes complicated. Furthermore, since the heating furnace is used for a long time to remove the background, the heating furnace deteriorates quickly and the consumption of the carrier gas increases. In addition, it is difficult to compare the obtained data because a plurality of types of temperature rise profiles are used.

The present invention has been made in view of the above circumstances, and does not require the above-mentioned problems, that is, time and effort.
A background removal method for an inductively coupled plasma mass spectrometer using a heating vaporization introduction device that can easily remove the background, easily compare data, does not cause deterioration of the heating furnace, and consumes a small amount of carrier gas. It is intended to provide.

[0006]

According to the present invention, there is provided a method for removing a background of an inductively coupled plasma mass spectrometer using a heating vaporization introducing apparatus, wherein an analysis sample is heated by a background removing temperature rising profile having a plurality of stages. Then, the vaporization temperature of the binding ions is specified, and the analysis sample is heated using a temperature rising profile for detection provided with an ashing stage at a temperature corresponding to the vaporization temperature of the binding ions.

[0007]

FIG. 1 is a graph showing an example of a background removal temperature rise profile used in a background removal method of an inductively coupled plasma mass spectrometer using a heated vaporization introducing apparatus according to the present invention, and FIG. FIG. 3 is a graph in which a mass spectrum obtained by heating an analysis sample according to the heating profile for ground removal is superimposed thereon, and FIG. 3 is a heating profile for detection obtained based on the result of the heating profile for background removal. 5 is a graph in which a mass spectrum is superimposed on a profile.

[0008] In the following examples, it is assumed to create a detection Atsushi Nobori profile PR ₂ in the case of analyzing the Fe of mass number 56. First, it has set up an inductively coupled plasma mass spectrometer the mass number 56, to heat the analytical sample in the background removal for Atsushi Nobori profile PR ₁ shown in FIG. The background removal for Atsushi Nobori profile PR ₁ is the first to fifth stage S ₁ ~ a plurality of stages (5 stages in this embodiment)
Has S _5, the first to fifth stage S ₁ to S ₅
Are provided at equal intervals of 50 to 300 ° C.

[0009] An analytical sample heated to be analyzed using such background removal for Atsushi Nobori profile PR _1, it is possible to obtain a mass spectrum MS as shown in FIG. Here, MS ₁ to MS ₃ is the detected peak of Fe, MS ₄ are respectively a background increase due ArO. That is, the detection peaks MS _{1 to} M of Fe
The S ₃ so that the background increases MS ₄ by ArO is included as a noise. This is because the mass number of the bond ion ArO formed by combining Ar of the carrier gas and O of H ₂ O as a solvent of the analysis sample is substantially equal to Fe.

[0010] Background temperature rise profile P for background removal
R _1, since it has five stages of the first to fifth stage S ₁ to S _5, it is possible to accurately detect the temperature of ArO is vaporized. That is, the temperature corresponding to the second stage S ₂ is found to be the vaporization temperature of the background serving ArO.

Thus, if the vaporization temperature of the background binding ion (here, ArO) is determined,
The temperature to create a detection Atsushi Nobori profile PR ₂ provided with the ashing stage Sa (see FIG. 3). The detection for Atsushi Nobori profile PR _2, the back by the ground removing heating profile PR ₁ in stage (here having the highest temperature among the stages Fe is detected, the fourth
Stage S ₄ ) or a stage above it (here, the fifth stage
The temperature corresponding to the stage S ₅₎ is provided with a vaporization stage Sb.

Such a temperature rise profile PR ₂ for detection
When the analysis sample is heated with ArO, ArO
Is vaporized in the ashing stage Sa. Therefore, A
rO, as shown by MS ₄ in FIG.
Is detected. On the other hand, Fe
As shown in S _3, vaporized in the vaporization stage Sb, it will be detected. That is, Fe and ArO are completely separated from each other, and ArO does not become a background (noise) of Fe.

[0013]

According to the present invention, a background removal method for an inductively coupled plasma mass spectrometer using a heated vaporization introducing apparatus according to the present invention comprises the steps of: heating an analysis sample with a background removal temperature rising profile having a plurality of stages; The analysis sample is heated using the temperature rise profile for detection with the ashing stage provided at the temperature corresponding to the vaporization temperature of the bound ions, by specifying the vaporization temperature of the ions. Can be easily removed. This saves time and effort, makes it easy to compare data,
It is possible to reduce the consumption of the carrier gas without deteriorating the heating furnace.

[Brief description of the drawings]

FIG. 1 is a graph showing an example of a background removal temperature rising profile used in a background removal method of an inductively coupled plasma mass spectrometer using a heated vaporization introducing apparatus according to the present invention.

FIG. 2 is a graph obtained by superimposing a mass spectrum obtained by heating an analysis sample in accordance with the background removal temperature rising profile.

FIG. 3 is a graph in which a mass spectrum is superimposed on a detection heating profile obtained based on the result of the background removal heating profile.

FIG. 4 is a graph showing an example of a conventional heating profile.

[Explanation of symbols]

PR ₁ Temperature rise profile for background removal PR ₂ Temperature rise profile for detection S _{1 to} S ₅ First to fifth stages

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-239750 (JP, A) JP-A-59-84152 (JP, A) JP-A-58-37540 (JP, A) JP-A-1- 224645 (JP, A) JP-A-4-181644 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G01N 27/62-27/70 H01J 49/00-49/48 G01N 21/31 G01N 21/73 G01N 21/74

Claims (2)

(57) [Claims] When introducing an analysis sample into an inductively coupled plasma mass spectrometer using a heating vaporization introducing device, heating to separate an element to be detected from a bond ion serving as a background that hinders the detection of the element. In the background removal method for an inductively coupled plasma mass spectrometer using a vaporization introduction device, the analysis sample is heated by a background removal heating profile having a plurality of stages to identify the vaporization temperature of the bond ions, Method for removing background of inductively coupled plasma mass spectrometer using heated vaporization introducing device, characterized in that an analysis sample is heated using a detection heating profile provided with an ashing stage at a temperature corresponding to the vaporization temperature of the sample . 2. The mass of an inductively coupled plasma using a heating and vaporizing introduction device according to claim 1, wherein the stages of the background removal temperature raising profile are provided at equal intervals of 50 to 300 ° C. Background removal method for analyzer.